Edison and bayonet light bulb mountings are known to pose potential shock hazards, but have been used worldwide for many decades and continue to be used in huge numbers. These mountings represent the only exception in the relevant safety specifications, since, in spite of many years of effort, no useful alternative existed.
The drafts for the standards, which have been available internationally since 1975, place strict requirements for a new socket/mounting system.
The task of the invention is to describe a new socket and a corresponding safe-to-touch mounting which presents no danger, either when the lamp is taken out or during insertion. For such a new socket/mounting system, all other requirements of the standard drafts must also be taken into consideration.
The solution according to the invention to solve this task consists in designing the contact system as a safe-to-touch, pluggable pin contact system, which is arranged at the axial end surface of the socket and has at least two axial pins, while the socket is provided with snap-in profiles, so that the diameter of the socket and of the contact system is smaller than the diameter of the Edison or bayonet system to be replaced.
Only with the arrangement of the contact pins on the front face of the socket according to the invention can the diameter of the new system be kept so small that, with regard to size, the previous dimensions of the Edison or bayonet mountings can be achieved.
It is especially favorable to make the socket have a circular cross-section with two circular segments, which permits one to bring the snap-in profiles within the circular shape.
The snap-in profiles on the socket are expediently designed as a rigid profile, which secures seating of the lamp in the mounting, together with the corresponding spring-loaded catches.
A cost-saving and reliable solution consists in making both catches from nonmetallic material and to mold them into the insulating part. As a result of this, in spite of the small dimensions, the prescribed safety distances can be maintained.
In the new socket/mounting system, coding can also be provided which will prevent inadvertent use of lamps in mountings which require different operating conditions. This can involve, for example, different operating voltages, impermissible power in the lamp in a light fixture or other operating conditions.
The contact system according to the invention also facilitates the insertion and removal of lamps. In order to make this process even safer, it is furthermore proposed to have a locking incline in the mountings at an angle of 45.degree. or less, which makes a better sensation of snapping-in of the socket in the mounting. Such a locking incline provides a sufficient axial force component to hold the socket in the mounting. This function can be further improved by providing a limit to the plug-in stroke, which limits the plug-in stroke in the region of the locking incline. As a result of this, the axial force component, which is produced by the locking incline, is retained even when the lamp is fully plugged in, and ensures nonpositive and positive locking of the lamp in the mounting.
The plugging-in of the lamp is facilitated according to the invention by the fact that a plug-in incline of 30.degree. or less is present.
In order to fulfill the requirements of touch safety but also to protect the spring-loaded catch in the mounting, it is furthermore recommended to provide a protecting collar around the plug-in openings for the pins of the socket in the mounting, which also surrounds the spring-loaded catches in the mounting. Positive locking guides facilitate the finding of the holes for the pins within the protective collar.